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# Disease Spirits

#### by David M Woods

Ars Magica is a Registered Trademark of Trident Inc. Original Ars Magica material Copyright 1998 by Trident Inc. All Rights Reserved. Used without permission. Any use of Trident Inc.'s copyrighted material or trademarks in this file should not be viewed as a challenge to those copyrights or trademarks.

These rules rely on the premise that diseases in Mythic Europe are caused by certain types of Spirit. These rules are a compilation and reworking of various Ars Magica sources; More Mythic Places, Black Death and Hedge Magic.

## Preface

Disease Spirits are usually aligned to the Magic Realm although Divine, Infernal and Faerie Disease Spirits exist as well. These Spirits possess animals, plants and people, causing disease. They are attracted to certain types of area and host. Beliefs concerning foul airs causing disease are due to many diseases favouring such areas. Disease Spirits also cause imbalances in the host's humours, that in turn, gives rise to the symptoms. Medicine works by helping to re-balance the body's humours which in turn encourages the Spirit to leave.

Particular types of Disease Spirit can summon others of their kind when within a host. By this process epidemics can occur under the right conditions. Fires, incense and pungent herbs can create an unpleasant environment for such spirits. Disease Spirits will tend to avoid areas they find unpleasant and tend not to summon others if their host is within such environments. By these methods many epidemics can be contained. However, particularly aggressive Spirits may not be discouraged.

A person can resist possession by a disease Spirit but his chances of success depend on many factors. A person with a strong constitution, a good diet and active lifestyle is less likely to fall ill.

Disease Spirits are very common in Mythic Europe, fortunately most are generally non-fatal like Colds and Flu. Also many are picky over whom they possess. Many types will not possess a host who has been possessed by another of its kind. Many are attracted to specific groups like children, drunks, gluttons, whores and whoremongers. Many are only interested in the elderly.

## Game play

### Disease Spirits

Disease Spirits fall under the Hermetic Form of Vim when outside a host. Once in possession the host shields the Spirit and can it only be affected indirectly. Through sympathetic magic appropriate to the host body (Herbam, Animal or Corpus) the Spirit may be affected. Creo magic can be used to expel the possessing Spirit as returning the body to a more perfect state, sympathetically banishing the Spirit to its home Realm. Conversely Perdo magics actually summon a Disease Spirit directly into a host.

A Disease Spirit is defined by the following stats.

Might: The penetration total of any spell must exceed the Spirit's Might. This includes Creo Magics cast on hosts. In addition, the Level of any Creo spell must also equal or exceed the Might of the Spirit to banish it.
Virulency: The bonus the Spirit applies to its attempts to possess.
Summoning: The ability to summon others when within a host. How often depends on the Spirit, ranging from never to very often.
Effects: This section defines the effects of the disease.
Recovery: The conditions under which the body may attempt to expel the spirit and any long term effects.

### Appearance and Detection

Disease Spirits come in many shapes and sizes; in fact each is unique. Human Disease Spirits sometimes appear as humans showing extreme symptoms of the disease. Some appear as nightmarish animal forms or even a mist containing a swarm of lights. A Second Sight + Per roll of 12+ can enable Disease Spirits to be seen, as can a Vim version of `Vision of the Haunting Spirit'. However most Disease Spirits are adept at hiding.

### Magic Resistance

Parma Magica and any other magical resistance can block possession. This follows the standard ArM4 rules for penetration, use Vim to calculate the effective ward level of a Parma Magica. The Spirit's penetration total equals its Might + stress die. Aegis of the Heath (AotH) can block entry to free disease Spirits, but not when in possession of a host. Spirits brought in or summoned into an AotH can operate but suffer a penalty on possession rolls equal to the magnitude of the AotH.

This means Magi are generally well protected against disease. However, spirits will often wait for the right moment to attempt the possession, especially if the target is very tempting. Every sunset and sunrise Parma drops for at least one minute, this is more than enough time.

### Aura Interaction

Possession rolls by Disease Spirits are not so strongly affected by Auras as other tests. Half the effective level of any Aura (round down) to determine the bonus or penalty applied to the Spirit's possession attempts.

## Mechanics

When a Disease Spirit attempts to possess a host the Spirit and the Target make an opposed test.

The Spirit Rolls: Virulency + Aura Interaction + Environmental Modifier + Stress Die
The Target Rolls: Sta + Health Modifier + Wound and Fatigue Penalties + Stress Die

If the Spirit exceeds the Target's roll it has succeeded in possessing the Target. The same Spirit will not make more than one attempt on any one target.

### Environmental Modifier

Most Diseases thrive in damp, cold, lightless and foul-smelling places. Within their favoured environment they receive a bonus on possession and may receive a penalty outside it.

Environment | Modifier
Ideal | +3
Good | +2
Fair | +1
Average | 0
Unpleasant | -1
Hostile | -2
Very Hostile | -3

### Health Modifiers

Age Modifier: A person's age greatly affects his or her ability to resist.

Age | Modifiers
0-5 months | -3
6 months -2 years | -1
3 - 11 | +1
12-24 | +2
25-34 | +1
35-39 | 0
40-44 | -1
45-49 | -2
50-54 | -3
55-59 | -4
60+ | -5

Lifestyle & Diet: These two factors also play a part in resisting disease. A poor diet may be due to lack of quantity or quality. A good diet represents a balanced mix of meat, vegetables and other staples. An excessive diet represents an indulgent eating (or drinking) pattern. An average diet can be a balance of any of the other factors.

Activity Level / Diet | Poor | Average | Good | Excessive
Sedate | -2 | -1 | 0 | -2
Moderate | -1 | 0 | +1 | -1
Active | 0 | +1 | +2 | 0

Miscellaneous: These factors apply to only some characters.

Longevity Potion: +Potion Bonus
Rapid Convalescence: +3
Healer Exceptional Talent: +Score

## Disease Spirit Guidelines

### Might

A Disease Spirit's Might should be around 5 for annoying infections like Warts and Colds. More serious conditions like Fever and Pneumonia should be around 15. Very serious disease like Leprosy should be around 20. Black Death is rated at 30.

### Virulency

Break out the medical dictionary or just guess. The Table below should be used to assign a reasonable value according to the disease's properties.

Very Low | -9
Low | -6
Below Average | -3
Average | 0
Above Average | +3
High | +6
Very High | +9

### Summoning

Infectious diseases Summon. Non-infectious diseases don't. The number, frequency and aggression of these summoned Spirits is at the SG's discretion. A summoned Spirit must possess a new host before the original Spirit can summon another. The summoned Spirit must stay close to the summoner's host until it finds a host.

Never | The disease is not infectious
Very Rarely | The disease rarely summons others. Perhaps as little as once per year
Rarely | Perhaps once per month
Uncommonly | About once per week
Commonly | About once per day
Often | About 6 time per day
Very Often | Unlimited

### Effects and Recovery

Another job for the medical dictionary, roughly convert the real world facts into ArM4 mechanics.

## Examples

### Cold

Might: 5
Virulency: High +6
Summoning: Often
Effects: Gives the afflicted a common cold within a few hours. While sick the target is always Winded.
Recovery: Roll Sta + Stress Die of 6+ after every good night's rest, with a +1 modifier for every consecutive morning. Roll every week when no rest is found.

### Headache

Might: 8
Virulency: Average +0
Summoning: Never
Effects: Gives the afflicted host a bad headache. -1 to all actions.
Recovery: Roll Sta + Stress Die of 6+ every morning, with a +1 modifier for every consecutive morning.

### Warts

Might: 6
Virulency: Below average -3
Summoning: Rarely
Effects: Gives the afflicted host a large wart.
Recovery: If the Wart is physically removed, Roll Sta + Stress Die of 6+. Failure means the wart returns.

### Fever

Might: 12
Virulency: Average +0
Summoning: Commonly
Effects: The host develops a high temperature within ten minutes. While feverish the victim is always Weary (-1). Roll Sta + Stress Die of 6+ every day or become worse. Each failure results in another drop in fatigue level. After the host becomes unconscious Body Levels are lost.
Recovery: Once every two days the host may make a Sta + Stress Die roll of 9+ for recovery. Fatigue levels are recovered at a rate of one per day. Body Levels are recovered according to the standard rules.

### Skin Rash (Scrofulous)

Might: 10
Virulency: Above Average +3
Summoning: Uncommonly
Effects: The victim develops an itching skin rash covering half of a limb or its equivalent within an hour. -2 to all Com and Pre rolls is the rash is visible.
Recovery: Once per week, or twice if treated, Roll Sta + Stress Die of 6+. The host receives a +2 modifier for every consecutive week of possession..

### Toothache

Might: 12
Virulency: Average +0
Summoning: Never
Effects: Gives the afflicted host a toothache. -2 to all mental activities.
Recovery: No recovery rolls are allowed without some kind of treatment. Removing the tooth works but causes a light wound.

### Consumption (Tuberculosis)

Might: 15
Virulency: Low -6
Summoning: Uncommonly
Effects: Within a few hours the host becomes short of breath and becomes Winded. The victim cannot recovery this level normally. Each month the host must make a Sta + Stress die roll of +3 or lose another fatigue level. A roll of +6 gains the host back a fatigue level. Moving to a warm dry environment gives a +3 bonus to this roll.
Recovery: No recovery rolls are allowed without some kind of treatment (Medicine or Herbalism score of 3+). If treatment is given a Sta + Stress die roll of 6+ will cure the victim. Most people must live with this disease until they die.

### Leprosy

Might: 18
Virulency: Very Low -9
Summoning: Rarely
Effects: A full year passes before the first symptoms appear. Initially a skin rash (see Scrofulous) in the extremities. It slowly worsens to include loss of feeling and general weakness. -1 to Qik per year infected. In addition, -1 Sta, Str, or Dex is suffered per year (player's choice). Unless extreme care is taken, fingers, toes, and other extremities are lost due to accident and gangrene.
Recovery: No recovery rolls are allowed without some kind of treatment (Medicine or Herbalism score of 6+). Most people must live with this disease until they die.

### The Pox (Smallpox)

Might: 20
Virulency: High +6
Summoning: Often
Effects: About four days after infection, the host is beset by chills, headache and fever (se above). A few days later, these symptoms disappear and the pox appears, covering the victim's body with numerous lesions.
Recovery: If not treated the victim is allowed one roll a week after the appearance of the pox. The victim must make a Sta + Stress die of +6 or they will eventually die. The SG may allow further rolls if skilled treatment is provided. If the host survives they gain the Disfigured flaw.

### Heart Attack

Might: 20
Virulency: Average +0
Summoning: Never
Effects: A sharp pain in the chest.
Recovery: Unless the victim makes a Sta + Stress die roll of 12+ they will die. If the victim survives they lose 5 points of Sta.

### The Black Death

Might: 30
Virulency: Very High +9
Summoning: Very often
Effects: If the Spirit succeeds by 6 or more points the host develops the Pneumatic form of the disease, else they develop the Bubonic form.
Pneumatic Effects: The victim develops a cough about 3 hours after infection. This cough worsens quickly and kills within 2-12 hours, unless a magical cure is applied.
Recovery: None, unless magical cures are applied.
Bubonic Effects: Within a few hours, the victim's neck and underarm glands swell painfully. The victim loses 1 Body Level and 1 point from Str, Sta, Qui and Dex, per day.
Recovery: The victim must attempt a Sta + Stress die of +9 each day to recover. The SG may allow further rolls if skilled treatment is provided. Lost characteristic points recovery as Body levels, too within one point of their original values.